Conventionally, catalysts in each of which an active metal is supported by a catalyst support having a large specific surface area have been widely used for industrial purposes. Some already known examples of the method of making an active metal be supported by a catalyst support are what are termed impregnation methods, such as the evaporation-to-dryness method, the equilibrium adsorption method, and the pore-filling method, as well as the ion-exchange method. In the evaporation-to-dryness method, a support is firstly immersed in a metal-containing solution and then the solvent is evaporated to make the active metal be supported by the support. The evaporation-to-dryness method tends to cause agglomeration of the active metal, and leads to a relatively low dispersivity of the active metal. Consequently, the evaporation-to-dryness method has its own limits in enhancing the catalyst activity. In the equilibrium adsorption method, firstly, the support is immersed in a metal-containing solution, and then the excess solution is removed by filtration or the like to make only the active metal that is adsorbed to the support be supported by the support. The equilibrium adsorption method is capable of enhancing the degree of dispersivity of the active metal in comparison to the evaporation-to-dryness method. However, when the product catalyst is examined portion by portion, there exist portions where the active metal is agglomerated and there also exist other portions where the active metal is dispersed in a relatively uniform state. Accordingly, it is difficult to disperse the active metal uniformly across the entire body of the support, so that the equilibrium adsorption method has also its own limits in enhancing the catalyst activity. In the pore-filling method, a metal-containing solution is applied to the support little by little. When the surface of the support begins to get wet uniformly, the impregnation is finished. The pore-filling method is capable of making the active metal be supported by the support with a relatively favorable dispersivity, but the amount of the supported active metal is relatively small. Consequently, the pore-filling method has also its own limits in enhancing the catalyst activity. In the ion-exchange method, an active metal is made to be supported by the support by use of the ion exchange that takes place between the metal cation contained in the support and the metal cation to be supported. The ion-exchange method tends to be capable of making the active metal be supported by the support in a relatively highly-dispersed state in comparison to the above-described impregnation methods. However, in order to increase the amount of the supported active metal by increasing the exchange rate in a case where the ion-exchange is an equilibrium reaction, the ion-exchange operation needs to be repeated. Accordingly, the ion-exchange method has a problem of complex preparation for the catalyst in comparison to the above-described impregnation methods.
On the other hand, various catalyst supports have been developed thus far. For example, Japanese Unexamined Patent Application Publication No. 11-76820 (Document 1) discloses a catalyst for partially oxidizing carbon hydride, and the catalyst is made by fixing gold fine particles to a titanium-containing silicate porous material. The catalyst described in Document 1, however, is also manufactured by what is termed an impregnation method, and has its own limits in enhancing the catalyst activity.